KR100502767B1 - Two-stage liquid ring pumps - Google Patents

Abstract

The two stage liquid ring pump of the present invention has a structure between stages that facilitates separation of gas and liquid discharged from the first stage. The second stage has separate gas and liquid inlets for entering each of the separated gases and liquids into the second stage. This prevents any clogging of the second stage gas inlet by the liquid, thereby improving the performance of the pump.

Description

Two stage liquid ring pump {TWO-STAGE LIQUID RING PUMPS}

The present invention relates to a liquid ring pump, in particular a liquid ring pump with two-stages gas pumping stages connected in series.

Two stage liquid ring pumps are known, for example, as disclosed in US Pat. No. 4,521,161 to Olsen et al. In such a general pump, the mixture of gas and liquid exits the first stage and moves to the inlet of the second stage. The liquid in this mixture is generally required to replenish the liquid exiting the gas in the second stage, for example with the gas from the second stage. However, since the liquid in the mixture obtained from the first stage can block the inlet of the second stage to some extent, the pressure difference that the pump can achieve is reduced, the volumetric capacity of the pump is reduced, and / or the power demand of the pump This can be increased.

It is therefore an object of the present invention to provide an improved two stage liquid ring pump in view of the foregoing.

More specifically, it is an object of the present invention to increase the pressure range and volumetric capacity and to reduce the power requirement of the two stage liquid ring pump.

These and other objects of the present invention are achieved in accordance with the principles of the present invention by providing a two stage liquid ring pump in which gas and liquid discharged from the first stage are facilitated through the structure between the stages. Furthermore, separate inlets are provided to allow each of the separated gas and liquid to enter the second stage. As a result, clogging of the liquid from the first stage to the second stage gas inlet is prevented by the liquid.

The features, characteristics and various advantages of the present invention will become more apparent from the accompanying drawings and the following detailed description of the invention which relates to preferred embodiments.

Since the configuration of the liquid ring pump and the configuration of the two stage liquid ring pump are already well known, the details of the structure and operation of such a pump will not need to be repeated here. However, the exemplary pump 10 shown in FIGS. 1 and 2 is basically similar to the pump disclosed in the aforementioned U.S. Patent No. 4,521,161, which is incorporated herein by reference, and with the pump illustrated in U.S. Patent No. 4,521,161. To facilitate the comparison, the elements of the pump according to the invention which are similar to the elements of the pump illustrated in U.S. Patent 4,521,161 use the same reference numerals as U.S. Patent 4,521,161. The new elements in the pump of the present invention, which are not coded in US Pat. No. 4,521,161, take on new reference numerals in units of 200.

As shown in FIG. 2, the first end 12 of the pump 10 is on the right side of the figure, and the second end 14 is on the left side of the figure. The first stage 12 pumps gas from the gas inlet 16 into the intermediate pressure passage and withdraws the gas and some excess pumped liquid from the first stage through the passage 26 between the stages. This gas and liquid mixture flows from right to left along the passage 26 as seen in FIG. 2.

While the gas and liquid mixture exiting the first stage 12 flows along the passageway 26 between the stages, the heavy liquid portion of the mixture attempts to fall to the bottom of the passageway 26 between the stages under the influence of gravity. There is a tendency. The portion of the passageway 26 between the stages adjacent to the second end 14 has a downwardly inclined ramp 226a leading to a recess 226b that is dug down in that passageway. The liquid moving along the passageway 26 between stages tends to separate from the gas and flow down ramp 226a into the recessed portion 226b of the lower portion. On the other hand, the gas remains above the liquid in the upper part of the passageway 26 between the stages above the lower recesses 226b.

The upper portion of the passageway 26 between the stages in the second stage head member 100 communicates with the second stage gas inlet passage 104. The second stage gas inlet passage 104 leads to another second stage gas inlet passage 94 of the second stage port member 90. Gas from the second stage gas inlet passage 94 is sucked into the working space of the second stage through the second stage gas inlet 292. (The second stage gas inlet 292 is not a new feature of the present invention, but is not indicated in the above patents of Olzen et al., And is indicated by reference numeral 200 units.) Second stage gas inlet passage 104 ) Is in communication with only the upper portion of the interstage passage 26, so that little or no liquid flows from the interstage passage 26 to the second stage gas inflow passage 104. Instead, gas is preferentially introduced into the second stage gas inlet passage 104 from the interstage passage 26. As a result, the amount of liquid flowing into the second stage through the second stage gas inlet 292 is greatly reduced. Accordingly, the phenomenon in which the second stage gas inlet 292 is blocked by the liquid from the interstage passage 26 is greatly reduced or eliminated.

Liquid does not enter the second stage through the second stage gas inlet 292 from the interstage passage 26 and is completely separated from the second stage head member 100 and the second stage port member 90 described below. Liquid passages are provided. The downward recess 226b of the passage 26 between the stages communicates with the liquid passage 204 of the second stage head member 100. The liquid passage 204 of the second stage head member 100 communicates with the liquid passage 294 of the second stage port member 90. The liquid passage 294 of the second stage port member 90 leads to the second stage liquid inlet 292a of the second stage port member 90, and directs liquid from the liquid passage 294 to the second stage gas. Inlet 292 is introduced into the working space of the second end 14 downstream in the direction of rotation of the second stage rotor blade 82. Thus, most of the liquid from the interstage passage 26 flows down through the recesses 226b of the interstage passage 26 and the liquid passages 204 and 294, downstream of the second stage gas inlet 292. Into the second end 14 through a second liquid inlet 292a separate. Since the second stage liquid inlet 292a is formed separately downstream of the second stage gas inlet 292, the disadvantage in the prior art of allowing both gas and liquid to flow through the single inlet to the second stage is substantially Removed. Thus, pump performance is greatly improved over the prior art.

In the exemplary embodiment described, the "land line" of the second stage extends immediately before and perpendicular to the central longitudinal axis of the rotor shaft 28. (Land refers to the position where the radially outer end of the rotor blade 82 is closest to the fixed housing 20 of the pump, and the land line extends radially from the outside of the rotor shaft axis to the position of the land.) FIG. 1 When viewed from the rotor, the rotor rotates clockwise. The angle of measurement from the land in the rotor rotation direction, in particular for the preferred position of the second stage liquid inlet 292a, is about 200 °. Continuing with this example, the second stage gas inlet 292 may begin to open at about 20 ° and close at about 160 °. The second stage gas inlet (not shown here, but similar to the inlet 96 of US Pat. No. 4,521,161, described above) may be open at about 258 ° and closed at about 340 °. All of these angles are merely examples, and other angles may be adopted if desired.

As mentioned above, the following elements not mentioned above are similar to those having the same reference numerals as identified above in US Pat. No. 4,521,161.

Reference numeral 18: outlet opening

Reference numeral 20: annular housing

Reference numeral 22: First stage fixed housing

Reference numeral 36: Side plates between ends

Reference numeral 60: Head member

Reference numeral 80: Annular shroud

Reference numeral 110: Bearing assembly

The foregoing description merely illustrates the principles of the invention, and it will be apparent to those skilled in the art that various modifications may be made without departing from the scope and spirit of the invention. For example, although this invention demonstrated the pump provided with the truncated cone-shaped port member like the port member 90, it is equally applicable to the pump provided with the port member of another form. Other known shapes include cylindrical port members and flat port members. The flat port member is related to U.S. Patent No. 3,108,738 to Ruhman, U.S. Patent No. 4,132,504 to Pitch, U.S. Patent No. 4,323,334 to Harvik, U.S. Patent No. 4,685,865, etc. Illustrated in the patent.

According to the present invention, there is provided a two stage liquid ring pump in which gas and liquid discharged from the first stage are facilitated through the structure between the stages, so that each separated gas and liquid can enter the second stage. By providing inlets of, any blockage of the second stage gas inlet by the liquid from the first stage is prevented, thereby increasing the pressure range and volumetric capacity and reducing the power requirement of the two stage liquid ring pump.

1 is an elevational view, partially taken away, of an exemplary embodiment of a two stage liquid ring pump constructed in accordance with the present invention, taken on the left side of FIG.

FIG. 2 is a view of the right side of FIG. 1, showing another elevational view of the pump of FIG.

<Description of the symbols for the main parts of the drawings>

10: pump

12: first stage

14: second stage

16: gas inlet

18: outlet opening

22: first stage fixed housing

24: second stage fixed housing

26: passage between stages

28: rotor shaft

36: side plate between ends

60: head member

70: bearing assembly

80: annular shroud

82: rotor blade

226a: downward slope ramp

226b: downward recess

Claims (3)

10. A two stage liquid ring pump comprising a first stage, a second stage, a first stage outlet for discharging a mixture of gas and liquid from the first stage, and a structure between the stage for separating the liquid and the gas. , A second stage gas inlet and a second stage liquid inlet for introducing each of said separated gases and liquids into said second stage. 2. The second stage of claim 1, wherein the second stage has a rotor that rotates in a predetermined direction, wherein the second stage liquid inlet is located downstream of the second stage gas inlet in the direction of rotation of the rotor. Single liquid ring pump. 3. The two stage liquid ring pump of claim 2, wherein the second stage liquid inlet is positioned approximately 40 ° past the closure of the second stage gas inlet in the direction of rotation of the rotor.